What types of OTC medicines treat diarrhea?Over-the-counter medicines are medicines you can buy without a prescription from your doctor. Some OTC medicines can help you feel better if you have diarrhea. These are called antidiarrheal medicines.

Antidiarrheal medicines include loperamide (1 brand name: Imodium) and bismuth subsalicylate (2 brand names: Kaopectate, Pepto-Bismol). Bismuth subsalicylate can also be used for upset stomach and as an antiemetic (a medicine that treats nausea and vomiting).

How do OTC antidiarrheal medicines work?Loperamide works by slowing down how fast things move through your intestines (bowels). This allows more fluid to be absorbed so that you have less diarrhea and more formed stools.